Basis Of Presentation (Details) $ in Thousands	4 Months Ended
	Jan. 22, 2017 USD ($) restaurant	Jan. 17, 2016 USD ($) restaurant	Oct. 02, 2016 USD ($)
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation | $	$ 3,981	$ 2,020
Jack in the box brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	2,261	2,253
Jack in the box brand restaurant operations [Member] | Entity Operated Units [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	419	413
Jack in the box brand restaurant operations [Member] | Franchised Units [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	1,842	1,840
Qdoba brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	712	674
Qdoba brand restaurant operations [Member] | Entity Operated Units [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	376	330
Qdoba brand restaurant operations [Member] | Franchised Units [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	336	344
Current Maturities of Long-Term Debt [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Unamortized Debt Issuance Expense | $			$ 1,600
Long-Term Debt, Net of Current Maturities [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Unamortized Debt Issuance Expense | $			$ 2,200